Japan's health ministry has issued a checklist of 13 coronavirus symptoms which indicate that a person should consult a medical expert immediately.
The list is designed for patients with mild symptoms who are recuperating at designated accommodation facilities or at home.
Tokyo Governor Koike Yuriko has outlined the steps the city's government would take if the prime minister declares a state of emergency over the coronavirus outbreak.
Koike said in a briefing on Friday that she will likely ask residents to stay at home, and request public facilities and event organizers to suspend the use of venues. She said specific requests would be decided after the central government issues relevant guidelines.
Japan's government has added pneumonia caused by a new strain of coronavirus to its list of designated infectious diseases.
The Cabinet approved an ordinance on Tuesday giving the illness the designation under the country's infectious disease and quarantine laws.